Burglar-alarm



UNITED STATES PATENT OFFICE.

JOHN ISRAEL, OF ST. LOUIS, MISSOURI.

BURG LAR-ALARM,

SPECIFICATION forming part of Letters Patent No. 386,134, dated July 17,1888.

Application filed May 21, 1888. Serial No. 274,463.

To aZ whom t may concern.-

Be it known that I, JOHN ISRAEL, of St. Louis, in the State of Missouri,have invented certain new and useful Improvements in Burglar-Alarms, ofwhich the following is a specification, reference being had io theaccompanying drawings.

My invention relates to detonating burglaralarms of the class shown inmy United States Patents Nos. 193,002 and 224,017.

The object of my present improvement is to provide mechanism fortripping the springplunger, which mechanism can be set to do thetripping from the outside of a door after it has been closed.

In the accompanying drawings, illustrating my invention, Figure l showsmy firing mechanism applied upon a doorjamb and a trip attachmentapplied to the door. Fig. 2 shows the trip attachment detached and theslide thrown forward into the tiring position. Fig. 3 shows the oppositeside of the trip attachment from that shown in Fig. 2, with the slidenot in the firing position, but thrown back, as in Fig. l.

Referring to the letters upon the drawings, A indicates a hollowcylinder provided with a spring-plunger, B, afulminate-slot, O, astandard, D, and a cap, E, all substantially as shown in my said PatentNo. 103,002.

F indicates a trip attachment to be used in connection with my saidburglar-alarm, in order to enable a person to properly set it foroperatiomwhen on a door, from the outside of the door.

Referring to Fig. 1, it will be seen that the detonating-plunger isdrawn back in the position for striking and exploding the fulminate; butit is so placed with respect to the door that (No model.)

the door would open without striking the end of the plunger and firingthe fulminate.

The trip attachment F, which can be operated from the outside of thedoor by means of the key O, is provided with a slide, P, connected inany suitable way-as, for example, by rod Q-to a rotary part, R, so thatthe key turning the part R will throw the slide ont or in. Vhen theslide is thrown out, as illustrated in Fig. 2, the door cannot be openedwithout tripping the plunger and exploding the fulminate, and thusgiving an alarm.

This alarm serves very etfeetually to protect the contents ofvacanti-ooms.

I do not confine my invention to the precise form of mechanismillustrated, because the form might be varied, the object being merelyto provide a moving part which can be operated by a key from the outsideof a door to engage with the end of a plunger when the door is opened.

Vhat l claim as new. and desire to secure by Letters Patent of theUnited States, is-

The combination, with the spring-plunger of a detonating burglar-alarm,ofa trip attachment, F, consisting of a slide, P, connected to a rotarypart, R, adapted to be turned by a key, O, from the outside of a door tothrow the slide P out of or into position to strike the spring-plungerand operate the alarm mechanism attached to the inside of a door, whenthe door is opened, substantially as set forth.

In testimony whereof I have hereunto subscribed iny name.

JOHN ISRAEL.

Witnesses:

JACOB BOWER, J. T. HooK.

